New porous materials for efficient natural gas storage

Natural gas, mainly composed of methane, has long been considered as a preferable energy alternative to traditional fossil fuels due to its lower CO2 emissions. However, a critical bottleneck for its use as a transportation fuel has been the development of materials capable of storing it in a sufficiently compact form at ambient temperature. In 2012, the US Department of Energy (DOE) set a very ambitious storage target for adsorbed natural gas at room temperature and moderate pressures —targets which, to this day, were not met by any material. Since the highest reported values were considerable lower, it has so far been unclear whether a material able to reach DOE targets could even be developed.

In a work recently published in Nature Materials, the Adsorption & Advanced Materials group, headed by Dr. David Fairen-Jimenez, has explored a new way to design a material able to meet the DOE targets. The study focuses on a family of porous materials called metal-organic frameworks (MOFs). MOFs are arguably the most promising class of gas storage materials due to their large surface areas, with values as high as 8,000 m2 per gram of material. Discovered about 20 years ago, MOFs are one of the most exciting advances in recent porous materials science, symbolizing the beauty of porous coordination polymers and the possibility of modifying their individual chemical and physical properties like in a molecular Lego.

By using recent developments in advanced manufacturing and engineering of MOFs, the study was able to produce the first material that reaches the previously unachievable DOE target. Remarkably, it also includes a 100% improvement over any previous material reported to date, reaching, within a small range of statistical error, the physical limit methane storage capacity at room temperature. Moreover, this new monolithic material exhibits an excellent combination of mechanical properties and structural resilience central to practical applications. These findings represent a substantial step in the application of conformed materials for energy storage and for tackling carbon emissions and global warming, as well as paving a way forward for greener cities.